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Everything You Ever Wanted to Know About Fiber Optics

Close-up view of illuminated fiber optic cables for high-speed data transmission

Intro

There are a huge number of terms and concepts to be familiar with when talking about fiber optics, so I'm going to try and cover the essentials here. From my notes and own experience.

Definitions

  • When we talk about fiber optics, we're talking about either single-mode or multimode. These are two very different technologies:
    • Multi-mode: less expensive, suitable for short or medium distances (<500m). Cables are generally orange.
    • Single-mode: more expensive, suitable for long distances (up to a few kilometers). Cables are generally yellow.

Cables

The connectors

There are many different connectors, I list here the main ones you're supposed to see in the industry.

Connector Picture
LC: Lucent Connector, Little Connector or Local Connector.
Note: This is now the standard for new installations. For both switches and fiber adapter panels.		 LC fiber optic connector with yellow cable.
SC: Subscriber connector, square connector or standard connector.
Note: Still common on fiber adapter panels.		 SC fiber optic connector with yellow cable.
ST:
Note: Mainly found on older installations.		 ST fiber optic connector with orange cable.

Multi-mode

  • Multimode fiber cable is prefixed with OM or il. There are five types of Multimode : OM1/il1, OM2/il2, OM3/il3, OM4/il4 and OM5/il5.
Standard OM1/il1 OM2/il2 OM3/il3 OM4/il4 OM5/il5
Distance (1 Gbits) 275 m 550 m 550 m 550 m 550 m
Distance (10 Gbits) 33 m 82 m 300 m 400 m 400 m
Distance (40 Gbits / 100 Gbits) Not Supported Not Supported 100 m 150 m 150 m

Single-mode

  • Single-mode fiber cable is prefixed with OS. There are two types of Single-mode : OS1 and OS2.
Standard OS1 OS2
Distance 10 km / 6 Miles 100 km / 62 Miles
Enforcement Indoor Outdoor

SFP / mini-Gbics

SFP (small form-factor pluggable) is a compact, hot-pluggable network interface module. (source: https://en.wikipedia.org).

SFP fiber optic transceiver module for high-speed data transmission.
Img. The std.rocks sfp module.

1 Gbit/s SFP module

  • SX: Multi-mode, 850 nm, 550m/1Gbits or 150m/4Gbits.
  • LX: Single-mode, 1 310 nm, up to 10 km.
  • EX: Single-mode, 1 310 nm, up to 40 km.
  • ZX: Single-mode, 1 550 nm, up to 80 km.
  • EZX: Single-mode, 1 550 nm, up to 120 km.

10 Gbit/s SFP+ module

They have the same format as SFPs, but their speed can reach up 10 Gbits.

  • SR: Multi-mode, 850 nm, up to 300m/10Gbits.
  • LR: Single-mode, 1 310 nm, up to 10 km.
  • LRM: Multi-mode, 1 310 nm, up to 0.22 km.
  • ER: Single-mode, 1 550 nm, up to 40 km.
  • ZR: Single-mode, 1 550 nm, up to 80 km.